San Francisco Giants vs Arizona Diamondbacks Prediction, 5/18/2026 MLB Picks, Best Bets & Odds

Game: San Francisco Giants vs Arizona Diamondbacks

Date: Monday, May 18, 2026

Location: Chase Field in Phoenix, AZ

TV: DBACKS.TV

Odds/Point Spread: San Francisco (+162) Arizona (-196)

The Arizona Diamondbacks (21-23) will try to beat the San Francisco Giants (19-27) at Chase Field on Monday. The moneyline on this game has San Francisco at +162 and Arizona is sitting at -196. The over/under has been set at 8.5. The starting pitchers will be Robbie Ray and Zac Gallen.

San Francisco has a slugging percentage of .365 and have been called out on strikes 358 times, while being walked on 94 occasions. They have earned 144 runs batted in and 367 hits on the campaign, while their batting average is .240. The Giants have hit 77 two-baggers as a squad and have smacked 33 baseballs out of the stadium. They have earned 149 runs and have an OBP of .289. As a team, the San Francisco Giants are knocking in 3.3 runs/g, which has them at 30th in baseball.

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The Giants hold a team earned run average of 4.03 for the year (14th in MLB), and the staff has rung up 358 batters. Giants pitchers have given up 46 long balls and 197 total runs (15th in baseball). Their pitching staff has walked 172 players from the other team and their FIP is 4.19 as a squad this season. San Francisco has surrendered 361 base knocks (8.1 per 9 innings) as well as 179 earned runs. They have earned a K/BB ratio of 2.08 and their pitching staff has earned a collective WHIP of 1.34.

The Giants bullpen have earned a save percentage of 61.5% and stepped onto the hill in 37 save situations. They have earned 8 saves over the course of the season and have blown 5 out of their 13 chances to get a save. The bullpen pitchers have inherited 66 base runners so far this season with 27.3% of them earned a run for their team. Giants relief pitchers have stepped onto the hill with runners on base 46 times as well as having 27 appearances in high leverage situations. The Giants have dispatched 146 relievers to the mound for the year. The relief pitchers have a total of 24 holds on the year (16th in the league).

The San Francisco Giants have accumulated 1,198 putouts over the course of the season, in addition to 449 assists and 24 errors. Their fielding percentage is at .986 which puts them in 19th in the majors, and have accumulated 47 double plays. The Giants have transformed 70.2% of balls hit into play into outs out of 3,594 innings, which has them sitting at 15th in baseball.

Ray (91-86 win-loss mark in his career) is the owner of a FIP of 3.85 and he has gone up against 6,300 hitters during his time in the majors. He has conceded 1,289 base knocks (7.8 hits per nine innings) and has had 628 free passes. His ERA is 3.91 (648 ER's allowed) and his WHIP is 1.286. Ray has taken the hill for 1,491 innings and is sitting with 1,783 strikeouts so far in his pro baseball career.

Arizona has a total of 37 home runs this year as well as 182 RBIs. They have 81 two-baggers, while getting a free base 129 times and earning 188 runs. The Arizona Diamondbacks have an on-base percentage of .302 and a batting average of .237 this year. The Diamondbacks hold a team SLG% of .388 and they average 4.37 runs per contest (15th in MLB). They have been rung up on 334 occasions (28th in the league) and have a total of 337 hits.

The Diamondbacks hold a team WHIP of 1.272 and have a FIP of 4.32 as a squad so far this season. They rank 10th in baseball as a pitching staff in total hits surrendered with 346. The Arizona pitching staff have relinquished 205 runs over the course of the season while holding a team ERA of 4.35 (183 earned runs conceded). They have earned a K/BB ratio of 7.60 (318 strikeouts vs 136 bases on balls). They have conceded 50 home runs and they relinquish 4.87 runs per 9 innings (23rd in MLB).

Arizona relievers have an inherited score rate of 27.6% out of their 58 inherited runners. Their relievers have come in 54 times in high leverage situations and on 41 occasions with base runners. Sitting with 47 save situations, the Diamondbacks have earned 28 holds in addition to 7 blown saves. They sit at 19th in baseball with a save percentage of 61.1%, and they have sent 142 relievers to the mound so far this year.

Out of their 3,411 innings on the field, the Diamondbacks have a efficiency on defense of 71.7% (6th in professional baseball). The Arizona Diamondbacks have gotten 26 double plays and have a fielding percentage of .987 (14th in baseball). The Diamondbacks have recorded 370 assists, 20 errors and have a total of 1,137 putouts during this campaign.

In his MLB career, Gallen has surrendered 894 hits and he has 1,089 strikeouts in 1,050 innings pitched. He has given up a total of 425 ER's while holding a WHIP of 1.173 and being the owner of a FIP of 3.6. He has a K/BB ratio of 3.22 and he has gone up against 4,335 opposing batters so far in his career. Gallen (67-56 career mark) has a 3.64 earned run average while allowing 7.7 hits per 9 innings.

Who will win tonight's MLB game against the spread or moneyline?

Tony Sink's Pick: Take San Francisco (+162)

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